Road Salt Application in Highland Creek Watershed, Toronto, Ontario - Chloride Mass Balance

Abstract

Occurrence of increasing chloride concentrations in urban streams of cold climates, mainly due to road salt application, has raised concerns on its adverse effects on aquatic and terrestrial ecosystems. Therefore, there is a need for a better understanding of processes associated with road salt application and subsequent discharge into the environment in order to develop management practices to minimize detrimental effects of chlorides. The chloride mass analysis for the Highland Creek watershed based on four years of hourly monitoring data indicates that approximately 60% of the chlorides applied on the watershed enter streams prior to subsequent salting period, 85% of which occurs during the period between November and March. Contribution of private de-icing operations on chloride mass input within Highland Creek watershed was estimated to be approximately 38%, indicating its significance in overall chloride mass balance. Salt application rates, as well as chloride output in the streams, vary spatially based on land use, influencing chloride concentrations in surface waters. The estimated groundwater chloride concentration of 275 mg/L indicates that some aquatic organisms in Highland Creek would potentially be at risk even outside the winter period under dry weather flow conditions.

Hot, Salty Water: A Confluence of Issues in Managing Stormwater Runoff for Urban Streams

“…Finally, we applied a conversion of the specific conductivity data to an equivalent chloride concentration in units of mg/L. The literature provides several methods that utilize measured relationships between lab measured specific conductivity and chloride concentrations (see Perera et al ., ; Conrads et al ., ). For our field‐based sampling, we used the relationship provided by Windsor et al .…”

“…We then applied a drift correction as a linearly interpolated adjustment to the downloaded dataset in the manner of Perera et al . (). Finally, we applied a conversion of the specific conductivity data to an equivalent chloride concentration in units of mg/L.…”

Compost Biofilters for Protection of Environmentally Sensitive Areas Receiving Roadway Runoff

“…Runoff from roads has been implicated as a significant cause of freshwater impairment (Bartlett, Rochfort, Brown, & Marsalek, 2012;Gazendam, Gharabaghi, McBean, Whiteley, & Kostaschuk, 2009;. Hydrocarbons, chlorides, and heavy metals such as nickel, zinc, chromium, lead, and copper are characteristic of highway runoff (Hallberg, Renman, & Lundbom, 2007;Mayer et al, 2011;Perera et al, 2010Perera et al, & 2013Trenouth, Gharabaghi, & Perera, 2015;Trenouth et al, 2018;Salek et al, 2018). Diffuse sources of pollutants on roadways include automobile deterioration, tailpipe exhaust, and slow leaks of vehicle fluids (Thomson, McBean, Mostrenko, & Snodgrass, 1994).…”

Investigating the Spatial and Temporal Variability of Precipitation using Entropy Theory

“…An understanding of precipitation variability is also needed for flood and drought preparedness planning. There is a need to better understand the spatial and temporal variability in precipitation to more accurately model the hydrologic system and the health of aquatic life (Perera et al 2009;Perera et al 2010;Perera et al 2013;Betts et al 2014;Betts et al 2015;Sabouri et al 2013;Gazendam et al 2016). Parameters that represent this variability may be important factors to include in modeling studies (Vasiljevic et al 2012;Rudra et al 2015).…”